Home | History | Annotate | Download | only in component_updater 
      1 // Copyright 2014 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #ifndef COMPONENTS_COMPONENT_UPDATER_COMPONENT_UNPACKER_H_
      6 #define COMPONENTS_COMPONENT_UPDATER_COMPONENT_UNPACKER_H_
      7 
      8 #include <stdint.h>
      9 #include <string>
     10 #include <vector>
     11 
     12 #include "base/callback.h"
     13 #include "base/files/file_path.h"
     14 #include "base/json/json_file_value_serializer.h"
     15 #include "base/macros.h"
     16 #include "base/memory/ref_counted.h"
     17 #include "base/memory/scoped_ptr.h"
     18 #include "base/sequenced_task_runner.h"
     19 
     20 namespace component_updater {
     21 
     22 class ComponentInstaller;
     23 class ComponentPatcher;
     24 class OutOfProcessPatcher;
     25 
     26 // Deserializes the CRX manifest. The top level must be a dictionary.
     27 scoped_ptr<base::DictionaryValue> ReadManifest(
     28     const base::FilePath& unpack_path);
     29 
     30 // In charge of unpacking the component CRX package and verifying that it is
     31 // well formed and the cryptographic signature is correct. If there is no
     32 // error the component specific installer will be invoked to proceed with
     33 // the component installation or update.
     34 //
     35 // This class should be used only by the component updater. It is inspired by
     36 // and overlaps with code in the extension's SandboxedUnpacker.
     37 // The main differences are:
     38 // - The public key hash is full SHA256.
     39 // - Does not use a sandboxed unpacker. A valid component is fully trusted.
     40 // - The manifest can have different attributes and resources are not
     41 //   transcoded.
     42 //
     43 // If the CRX is a delta CRX, the flow is:
     44 //   [ComponentUpdater]      [ComponentPatcher]
     45 //   Unpack
     46 //     \_ Verify
     47 //     \_ Unzip
     48 //     \_ BeginPatching ---> DifferentialUpdatePatch
     49 //                             ...
     50 //   EndPatching <------------ ...
     51 //     \_ Install
     52 //     \_ Finish
     53 //
     54 // For a full CRX, the flow is:
     55 //   [ComponentUpdater]
     56 //   Unpack
     57 //     \_ Verify
     58 //     \_ Unzip
     59 //     \_ BeginPatching
     60 //          |
     61 //          V
     62 //   EndPatching
     63 //     \_ Install
     64 //     \_ Finish
     65 //
     66 // In both cases, if there is an error at any point, the remaining steps will
     67 // be skipped and Finish will be called.
     68 class ComponentUnpacker : public base::RefCountedThreadSafe<ComponentUnpacker> {
     69  public:
     70   // Possible error conditions.
     71   // Add only to the bottom of this enum; the order must be kept stable.
     72   enum Error {
     73     kNone,
     74     kInvalidParams,
     75     kInvalidFile,
     76     kUnzipPathError,
     77     kUnzipFailed,
     78     kNoManifest,
     79     kBadManifest,
     80     kBadExtension,
     81     kInvalidId,
     82     kInstallerError,
     83     kIoError,
     84     kDeltaVerificationFailure,
     85     kDeltaBadCommands,
     86     kDeltaUnsupportedCommand,
     87     kDeltaOperationFailure,
     88     kDeltaPatchProcessFailure,
     89     kDeltaMissingExistingFile,
     90     kFingerprintWriteFailed,
     91   };
     92 
     93   typedef base::Callback<void(Error, int)> Callback;
     94 
     95   // Constructs an unpacker for a specific component unpacking operation.
     96   // |pk_hash| is the expected/ public key SHA256 hash. |path| is the current
     97   // location of the CRX.
     98   ComponentUnpacker(const std::vector<uint8_t>& pk_hash,
     99                     const base::FilePath& path,
    100                     const std::string& fingerprint,
    101                     ComponentInstaller* installer,
    102                     scoped_refptr<OutOfProcessPatcher> out_of_process_patcher,
    103                     scoped_refptr<base::SequencedTaskRunner> task_runner);
    104 
    105   // Begins the actual unpacking of the files. May invoke a patcher if the
    106   // package is a differential update. Calls |callback| with the result.
    107   void Unpack(const Callback& callback);
    108 
    109  private:
    110   friend class base::RefCountedThreadSafe<ComponentUnpacker>;
    111 
    112   virtual ~ComponentUnpacker();
    113 
    114   bool UnpackInternal();
    115 
    116   // The first step of unpacking is to verify the file. Returns false if an
    117   // error is encountered, the file is malformed, or the file is incorrectly
    118   // signed.
    119   bool Verify();
    120 
    121   // The second step of unpacking is to unzip. Returns false if an error
    122   // occurs as part of unzipping.
    123   bool Unzip();
    124 
    125   // The third step is to optionally patch files - this is a no-op for full
    126   // (non-differential) updates. This step is asynchronous. Returns false if an
    127   // error is encountered.
    128   bool BeginPatching();
    129 
    130   // When patching is complete, EndPatching is called before moving on to step
    131   // four.
    132   void EndPatching(Error error, int extended_error);
    133 
    134   // The fourth step is to install the unpacked component.
    135   void Install();
    136 
    137   // The final step is to do clean-up for things that can't be tidied as we go.
    138   // If there is an error at any step, the remaining steps are skipped and
    139   // and Finish is called.
    140   // Finish is responsible for calling the callback provided in Start().
    141   void Finish();
    142 
    143   std::vector<uint8_t> pk_hash_;
    144   base::FilePath path_;
    145   base::FilePath unpack_path_;
    146   base::FilePath unpack_diff_path_;
    147   bool is_delta_;
    148   std::string fingerprint_;
    149   scoped_refptr<ComponentPatcher> patcher_;
    150   ComponentInstaller* installer_;
    151   Callback callback_;
    152   scoped_refptr<OutOfProcessPatcher> out_of_process_patcher_;
    153   Error error_;
    154   int extended_error_;
    155   scoped_refptr<base::SequencedTaskRunner> task_runner_;
    156 
    157   DISALLOW_COPY_AND_ASSIGN(ComponentUnpacker);
    158 };
    159 
    160 }  // namespace component_updater
    161 
    162 #endif  // COMPONENTS_COMPONENT_UPDATER_COMPONENT_UNPACKER_H_
    163